A number of diseases involving the intestinal and urinary tracts can result in the construction of an artificial outlet on the abdominal area for stools and/or urine; this is referred to as a stoma.
A diversion of the large intestine into the abdominal wall is referred to as a colostomy. The diversion of the small intestine is referred to as an ileostomy and when urine is disposed of through an artificial opening in the abdominal wall one refers to a urostomy. Usually a stoma patient is totally dependent on a well-functioning external collection device attached to the peristomal skin.
Over the years a large variety of stoma appliances has been developed. Patients with a colostomy collect the relatively normal faeces in closed pouches which are usually changed several times a day. Patients with an ileostomy collect their relatively liquid stool in drainable pouches, the opening of which can be opened and closed with a tail clip. Patients with a urostomy collect their urine in a pouch with a drain tap. Ileostomy and urostomy pouches are usually changed once a day.
Stoma appliances can be divided into two main systems; the one-piece system and the two-piece system.
In case of a one-piece stoma system, the body side wafer, which consists of a special adhesive, is an integral part of the pouch. This type of pouch is designed to be fixed directly to the skin and has the advantage that the total surface of the adhesive layer is flat and flexible, which allows it to follow the contours of the skin easily. However, the major disadvantage of a one-piece system is that the adhesive has to be removed from the skin with every pouch change, which may cause skin irritations.
In case of a two-piece stoma system, the body side adhesive layer and the pouch are two separate components. First one attaches a special body side wafer with flange onto the skin. This flange is usually made from plastic and is circularly shaped with an upstanding or projecting rib as a coupling member. The stoma pouch is also provided with a circular coupling member which can be attached on or around the projecting rib of the body side flange. A major advantage of a two-piece stoma system is that the peristomal skin is not disturbed during pouch changes as the adhesive part stays in place. A major disadvantage of a two-piece stoma system is that the body side adhesive wafer is far less flexible and flat compared with a one-piece system because of the rigidity and the higher profile of the built-in coupling member, which makes it less suitable for stomas positioned in difficult areas such as folds and irregularities of the skin. The design of most two-piece stoma systems is based on the two-piece stoma system designed by Steer et al. (British patent application 1,571,657). This stoma system consists of a body side wafer produced from a special hydrocolloid adhesive, covered by a thin polyethylene film, on which a circular polymeric flange with an upstanding or projecting rib has been attached which functions as a coupling member. The two-piece stoma system developed by Steer et al. is characterized by its property that all stoma appliances and stoma pouches within this system are provided with a polymeric coupling member with a circular channel, made to snap tightly over the projecting rib on the body side flanges. The projecting rib fits exactly in between the two walls of the channel in the coupling member of the stoma pouch.
Up until now various bonding techniques have been applied to attach a further component of the stoma system onto a body side wafer. For example a pouch onto the body side wafer in case of a one-piece stoma system, or a flange onto the body side wafer in case of a two-piece stoma system. These methods comprise heat sealing and gluing, using for example a double-sided adhesive or a hot-melt.
In the case of heat sealing, a further component such as the flange for example, is welded by applying heat locally on the welding area of the body side wafer. However this is not possible with the two-piece stoma system of Steer et al., since the relatively thick welding area of the flange hinders the transmission of heat to the thin film on the body side wafer. In other words, the polymeric flange would already melt and deform before the heat could reach the polymeric foam or film layer to be welded on the body side wafer.
Alternatively, the flange can be attached to the polymeric foam layer of the body side wafer by means of double-sided adhesive tape. This method, which is commonly used, consists of die-cutting circular adhesive rings from double-sided pressure sensitive adhesive tape that corresponds in size with the welding area of the flange. When such a double-sided adhesive washer is pressed together between the body side wafer and the welding area of the flange, a reliable bond can be obtained. The major disadvantage of this method is that it is a laborious intensive and expensive process.
Alternatively, the flange can be bonded to the polymeric foam layer of the body side wafer with the use of glue, usually a so-called ‘hot melt’. This heat-activated glue is manually or automatically applied between the flange and the appropriate surface of the body side wafer and when the two parts are pressed together—and in case of a hot melt, after cooling down—a good bond is be obtained. The major disadvantage of this method is that manual bonding of the flange is very laborious intensive and in the case of a more automated production method the bonding process, owing to the need for accurate dosage, is very complicated and requires high investments.
It is an object of the present invention to attach a further component of the stoma system onto a body side wafer with an improved bonding.